CUC INTERNATIONAL INC. AND SUBSIDIARIES EXHIBIT 15-LETTER RE: UNAUDITED INTERIM FINANCIAL INFORMATION June 13, 1997 Shareholders and Board of Directors CUC International Inc. We are aware of the incorporation by reference in the following Registration Statements of our report dated June 13, 1997 relating to the unaudited condensed consolidated interim financial statements of CUC International Inc. that are included in its Form 10-Q for the quarter ended April 30, 1997: Form S-3s, 33-30306, 33-47271, 33-58598, 33-63237, 33-95126, 333-11035, 333-13537, 333-17323, 333-17411, 333-20391, 333-23063 and 333-26927 Form S-8s, 33-17247 CUC International Inc. 1985 Non-Qualified Stock Option Plan 33-17248 CUC International Inc. 1985 Incentive Stock Option Plan 33-17249 CUC International Inc. 1987 Performance Share Stock Option Plan 33-26875 CUC International Inc. 1987 Stock Option Plan 33-75682 CUC International Inc. 1987 Stock Option Plan as amended 33-93322 CUC International Inc. 1987 Stock Option Plan as amended 33-41823 CUC International Inc. 1990 Directors Stock Option Plan 33-48175 Entertainment Publications Inc. 1988 Non-Qualified Stock Option Plan 33-58896 CUC International Inc. 1992 Bonus and Salary Replacement Stock Option Plan 33-91656 CUC International Inc. 1992 Bonus and Salary Replacement Stock Option Plan as amended 333-03241 CUC International Inc. 1992 Bonus and Salary Replacement Stock Option Plan as amended 33-74068 CUC International Inc. 1992 Directors Stock Option Plan 33-74066 CUC International Inc. 1992 Employee Stock Option Plan 33-91658 CUC International Inc. 1992 Employee Stock Option Plan as amended 333-00475 CUC International Inc. 1992 Employee Stock Option Plan as amended 333-03237 CUC International Inc. 1992 Employee Stock Option Plan as amended 33-75684 CUC International Inc. 1994 Employee Stock Purchase Plan 33-80834 CUC International Inc. Savings Incentive Plan 33-93372 CUC International Inc. 1994 Directors Stock Option Plan 333-09633 Sierra On-Line, Inc. 1987 Stock Option Plan 333-09637 Sierra On-Line, Inc. 1995 Stock Option and Award Plan 333-09655 Papyrus Design Group Inc. 1992 Stock Option Plan 333-22003 Knowledge Adventure 1993 Stock Option Plan Pursuant to Rule 436(c) of the Securities Act of 1933, our report is not a part of the registration statements prepared or certified by accountants within the meaning of Section 7 or 11 of the Securities Act of 1933. ERNST & YOUNG LLP Stamford, Connecticut